Given the mixed results and the high cost of subcutaneous injection of human recombinant GH therapy, a more natural approach to maintaining youthful health and vigor is to employ lifestyle choices that optimize the endogenous production of GH.

1. Deflate the spare tire. If you happen to suffer from fat stores concentrated centrally around the organs of the abdominal region, GH secretion will be even more impaired. Fortunately, research indicates that declining GH due to body fat gain is partially reversible with weight loss.1 Unfortunately, visceral adiposity is often an indicator of both insulin and leptin resistance and, as a result, can be very difficult to shed permanently. Fortunately recent work has led to the discovery of effective, natural methods for combating leptin resistance.2-4 For more information, see: "Deflating your spare tire for a longer, leaner life . . . Understanding the risks of leptin resistance" Life Extension, February 2009,5 and "Vindication" (How correcting a testosterone deficit can reduce abdominal adiposity), Life Extension, December 2008.6

3. Insist on a good night's sleep. The majority of GH secretion occurs at night during slow-wave (deep) sleep. Along with high-intensity exercise, another natural stimulus of endogenous GH secretion is sleep itself. It is well documented that inadequate sleep, irregular sleeping patterns, and poor quality sleep can substantially inhibit GH secretion.13,16 To optimize sleep, maintain good sleep hygiene habits: keep to a regular bedtime and wake-up time; do not consume alcohol or caffeine 4-6 hours before bedtime; and keep excess light and noise out of the bedroom.

4. Plan your last meal of the day carefully. Your last meal of the day is the most important for maintaining a robust GH/IGF-1 axis. A high-protein, low-carbohydrate snack before bedtime serves a dual purpose. First, it helps minimize insulin release and allows for maximum endogenous GH secretion. Second, important essential and conditionally essential amino acids found in protein assist endogenous GH secretion.13-15

5. Stay active! Exercise is a significant, natural optimizer of GH secretion.9 The type of exercise you do, as well the intensity and duration of your workouts, all play an important role in determining to what degree your training regimen contributes to GH secretion. A number of studies have suggested that the intensity necessary to trigger exercise-induced GH release corresponds to the lactate threshold -- the exercise intensity at which lactic acid accumulates in the blood.10 Exercise training above the lactate threshold appears to amplify the pulsatile release of endogenous GH at rest, increasing total secretion for at least 24 hours.11

Declining GH Levels and Poor Health

There are a number of lifestyle factors that lead to decreased GH and IGF-1 secretion. For example, multiple studies indicate that central adiposity (the accumulation of central body fat) accurately predicts GH decline.12,17-19

In addition, it is well established that poor nutritional status, inadequate sleep, and lack of physical fitness can all contribute to decreases in circulating GH and IGF-1, regardless of age.7

It seems clear that an unhealthy lifestyle contributes to somatopause both directly, by causing profound reductions in GH secretion, as well as indirectly, by promoting the physical and psychological symptoms of accelerated aging.